/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.catalina.ssi;

import java.io.IOException;
import java.util.Collection;
import java.util.Date;

/**
 * Interface used by SSIMediator to talk to the 'outside world' ( usually a
 * servlet )
 *
 * @author Dan Sandberg
 */
public interface SSIExternalResolver {
	/**
	 * Adds any external variables to the variableNames collection.
	 *
	 * @param variableNames the collection to add to
	 */
	public void addVariableNames(Collection<String> variableNames);

	public String getVariableValue(String name);

	/**
	 * Set the named variable to the specified value. If value is null, then
	 * the variable will be removed ( ie. a call to getVariableValue will
	 * return null )
	 *
	 * @param name  of the variable
	 * @param value of the variable
	 */
	public void setVariableValue(String name, String value);

	/**
	 * Returns the current date. This is useful for putting the SSI stuff in a
	 * regression test. Since you can make the current date a constant, it
	 * makes testing easier since the output won't change.
	 *
	 * @return the data
	 */
	public Date getCurrentDate();

	public long getFileSize(String path, boolean virtual) throws IOException;

	public long getFileLastModified(String path, boolean virtual)
			throws IOException;

	public String getFileText(String path, boolean virtual) throws IOException;

	public void log(String message, Throwable throwable);
}